Fats Oils and Grease in the Sewage System

Fats oils and grease (FOG) cause the majority of the problems and the headaches for municipal wastewater treatment systems. Fats oils and grease accumulations can cause sewage blockages, increase sewage odors particularly at lift stations, cause pipes corrosion, and general make wastewater treatment operators’ job much more difficult.

The source of Fats oils and grease in the sewage system is animal fat, vegetable fat, and oils used to cook and prepare food. While restaurants and food service companies produce the majority of FOG’s, its important not to overlook the amount of FOG’s added to the sewage system by individual households. Many communities require FOG pretreatment from industrial and commercial sources. However, since no there are no real restrictions on FOG disposal by residences, fats oils and grease will always get into the sewage systems and cause problems.

Problems with Fats Oils and Grease in the Sewage System

Fats oils and grease collect on the inside of sewage pipes. Much like arteriosclerosis in the human circulatory system, the accumulation of FOG’s in the pipes over time causes the pipes to constrict. This constriction reduces the sewage pipe capacity requiring more frequent pipe cleaning and more frequent pipe replacement. Further, this pipe constriction causes sewage backups and overflows.

FOGS’s are a difficult problem at lift stations as well. Since lift stations are a collection area, many times sewage is held long enough at a lift station to allow the grease to come out of solution and float to the top. This “grease cap” causes lift station odors and is generally pumped periodically adding to the manpower requirements and the costs for the municipal wastewater system. Lift stations can be treated biologically, here’s a link.

Finally, fats oils and grease cause problems at the wastewater treatment plant as well. FOG’s increase odors, make processing the wastewater more difficult, and increase the costs of operating the wastewater treatment facility.

Custom Biologicals has a number of biological products that help treat fats oils and grease. We have over twenty years experience in the biological reduction of FOG’s. Contact Custom for more information about how to treat your FOG problem.